A common technique for the installation of an exterior door includes the use of a pre-hung door. A typical pre-hung door 10, as shown in FIG. 1, includes a frame 12 and a door panel 14. The frame 12 typically includes a threshold 16, a header 18, a latch-side jamb 20 and a hinge-side jamb 22. A plurality of hinges generally mount the door panel 14 to the hinge-side jamb 22. The pre-hung door 10 may then be installed within a rough opening 24 of a building defined by at least a pair of studs 26 and a cross beam 28 (also known as a header). Sheathing 30, such as oriented strand board (OSB) or plywood may be applied around the rough opening 24 exterior and sheet rock may be applied as sheathing 30 on the interior of the rough opening.
Pre-hung doors 10 (also referred to as door units) are often preferred to separately hanging slab doors, especially for exterior entryways. This is because pre-hung doors 10 are pre-assembled to provide a tight fitting, substantially watertight seal between the frame 12 and the door panel 14. Pre-hung doors 10, however, can lack rigidity prior to installation. Thus, portions of pre-hung doors 10 have been found to bend, bow, twist, expand, contract or otherwise shift during shipping, handling and installation. These changes can reduce the quality of the pre-assembled seal between the frame 12 and the door panel 14. Returning to proper alignment and spacing between the door panel 14 and the surrounding frame 12 can be highly dependent upon installation practices and the skill of the installers. Properly positioning the pre-hung door 10 within the rough opening 24 can also be highly dependent upon installation practices and the skill of the installers.
To support and position the pre-hung door 10 within the rough opening, tapered shim pairs are conventionally used between the frame 12 and the studs 26. The tapered shim pairs may be used at several locations around the frame 12 to correspond with locations where the frame 12 is fastened around the rough opening 24.
There remains a need for an adjustable shim capable of taking up space between the outside face of the frame 12 and an opposing inside face of the studs 26 such that a pre-hung door 10 may be more easily and accurately supported and positioned within a rough opening 24.